Sharp Switching in Optical Couplers With Variable Coupling Coefficient

We report the switching behavior of a nonlinear optical coupler consisting of two straight waveguides forming a small angle. A very sharp switching can be obtained with these couplers. The switching power can be reduced up to two times compared to conventional couplers. The multiple switching can also happen at two and even more ranges of input powers. Because light switching is based on the optical Kerr effect, ultrafast switching is possible.